Device for the clamping of flexible printing blocks or stereos on the form-cylinder of copperplate or intaglio printing machines



March 14, 1933. P. GIETZ 1.900.986

DEVICE FOR THE CLAMPING OF FLEXIBLE PRINTING BLOCKS OR STEREOS ON THE FORM CYLINDER OF COPPERPLATE OR INTAGLIO PRINTING MACHINES Filed Aug. 6'. 1931' Flu .5.

Q-E- K d F? -El. f r J fin /N VEPN TOR Patented Mar. 14, 1933 SATES PATENT O F E PETER GIETZ, OF JOHANNISBERG-ON-THE-RHINE, GERMANY, ASSIGNOB. '10 MASGHI- NENFABR-IK JOHANNISIBERG G. M B. 11., OF GEISENHEIM-ON-THE-RHINE, GERMANY DEVICE FOR THE CLAMPING OF FLEXIBLE PRINTING BLOCKS 0R STEREOS' ON THE FORM-CYLINDER OF COPPEIRPLATE OR IN TAGLIO PRINTING MACHINES Application filed August 6, 1931, Serial No. 555,600, and in Germany December 29, 1930.

The present invention relates to a device for the clamping of flexible printing blocks or stereos on the form-cylinder of copperplate or intaglio printing machines, in which the bent-oil ends of the stereos or printing blocks are clamped in a dove-tail groove provided at the periphery of the form-cylinder and running parallel to the axial direction of the latter.

The present invention essentially consists therein, that the clamping wedge not only acts by means of its frontal side, but also by means of its under side upon the clamping ledge appertaining thereto pressing this clamping ledge, not being in immediate engagement with the dovetail groove, in the direction towards the second clamping ledge and also in the direction towards the axis of the form-cylinder, thus preventing a rising of the clamping ledge. In this way a pressure-resisting and accurately concentric surface of the form-cylinder will be attained.

The present invention has been schematically shown in the accompanying drawing by way of example, in which Fig. 1 represents a partial section through the form-cylinder of a copper-plate or intaglio rotary printing machine with the clamping and fixing device in accordance with the present invention, whilst Fig. 2 shows the one clamping ledge, not acting together with the clamping wedge, in front view.

Fig. 3 shows a cross section according to Fig. 2,

Fig. 4. illustrates the second clamping ledge acting in union with the clampin wedge in front view,

Fig. 5 in cross section and Fig. 6 in plan view and Fig. 7 the clamping wedge in front view,

Fig. 8 in cross section and Fig. 9 in plan view;

The clamping device is arranged in a dove-tail groove running parallel to the axis of the form-cylinder g at the periphery of same. The lateral faces of the dove-tail groove have been characterized by the letters a, Z and a1, 61, whilst its base is indicated by a, a1. At the ends of the printing blocks or stereos flanges i, being of the same thickness as the printing blocks or stereos, are bent, prior to being attached to the formcylinder, by means of a device adapted to that purpose, in such a manner, that the accurate length of'the printing blocks or stereos remains between the two flanges. The clamping ledge c is connected with the flange 2' and placed into the dove-tail groove, so that the bent printing block 6 hangs loosely round the form-cylinder. Subsequently the second clamping ledge d is suspended in the second flange z' of the printing block or stere0 e and placed into the groove. The connection of the two flanges i with the clamping ledges c and d is eflected in the case shown by way of example, by pins m, preventing a lateral displacement of the ends of the printing blocks or stereos against each other and rendering the employment of special screw connections unnecessary.

After lodging the clamping ledge d, the Wedge .f is driven in causing the clamping ledge d in the periphery of the form-cylinder 9 to be so displaced, that the printing block or stereo suspended to this ledge, is drawn round the form-cylinder. As a result of the pressure exercised by the wedge, the clamping ledge is simultaneously pressed in the direction of the axis of the formcylinder and thus firmly forced against the bottom of the dove-tail groove. In this way it will be possible to attain a pressure-resisting surface of the form-cylinder being placed accurately concentrically to the axis of the form-cylinder. The intermediate space it between the flanges '21 of the printing block or stereo e is reduced by this clamping action to the lowest possible amount, so that'any kind of filling material may be omitted and that the printing surface practically represents a homogeneous whole.

The ledge d, as well as the wedge is, has been provided with a scale rendering it possible'to ascertain at any time the then position of the wedge and to attach every subsequent printing block or stereo in connection with colour printing in exactly the same position as the first printing block or projection of said clamping 1e o posed between the under surface of said stereo, so that an accurate register is ensured.

I claim:

A device for clamping flexible printing blocks or stereos on the form-cylinder of copper-plate or intaglio printing machines, comprising in combination with the formcylinder having a groove of dove-tail shaped cross section in the periphery extending in the axial direction of said cylinder and with printing block or stereo bent at the ends, a clamping Wedge, a clamping ledge onone of said bent ends of said prlntin block or stereo cooperating with said we (ge, and a ge interwedge and the bottom of the dove-tail groove so that said ledge is not only moved in the direction of the circumference, but

also pressed in the direction towards the axis of the form-cylinder.

In testimony whereof I have aflixed my signature.

PETER GIETZ. 

